Green Manure Applications in Sustainable Agriculture

Green manures are cover crops grown specifically to be incorporated into the soil to enhance fertility, structure and biological activity. By returning biomass rich in nitrogen, phosphorus and organic carbon directly to the field, green manures stimulate soil microbial processes, accelerate nutrient cycling and build soil organic matter. Leguminous species such as vetches, clovers and milk vetch fix atmospheric nitrogen through symbiotic associations, reducing dependence on synthetic fertilisers. Non-leguminous grasses and cereals contribute high biomass and carbon inputs, promoting aggregation and moisture retention. Across diverse agroecosystems—from paddy rice rotations and temperate maize systems to orchards—green manuring has been shown to improve nutrient use efficiency, suppress soil-borne pathogens and stabilise yields under variable climatic conditions. Long-term benefits include enhanced soil structure, increased water-holding capacity and reduced greenhouse gas emissions, aligning productivity goals with ecological stewardship at the farm and landscape scale.

Research from Nature Portfolio

Effects of green-manure and tillage management on walnut orchards demonstrated that incorporation of legume cover crops significantly increased soil organic carbon, total nitrogen and available phosphorus in the rhizosphere, while also boosting enzyme activities (β-glucosidase, N-acetyl-glucosaminidase, acid phosphatase). Termination by flail mowing preserved microbial biomass and promoted tree vegetative growth. A comparative study of rice-based systems found that rotations including milk vetch green manure altered bacterial community structure in paddy soils, notably reducing nitrifying Nitrospirae and shifting Proteobacteria/Acidobacteria ratios, which correlated with higher rice productivity. Foundational work on Chinese milk vetch in a rice–legume rotation revealed that partial substitution of urea with green manure increased plant antioxidant enzyme activities, improved 15N recovery by over 70%, enriched beneficial microbial populations and enhanced rice biomass and nitrogen uptake.

Green Manure Applications in Sustainable Agriculture publication trend

The graph below shows the total number of articles in green manure applications in sustainable agriculture across all publications each year (not limited to Nature Index journals).

Technical terms

Green manure: A crop grown to be incorporated into soil to supply nutrients and organic matter.

Nitrogen mineralization: The microbial conversion of organic nitrogen compounds into plant-available inorganic forms.

Rhizosphere: The narrow zone of soil directly influenced by root secretions and associated microbial activity.

Soil organic matter: The fraction of soil composed of decomposed plant and animal residues, cells and tissues of soil organisms, and substances synthesized by soil biota.

References

1. Drive soil nitrogen transformation and improve crop nitrogen absorption and utilization - a review of green manure applications. Frontiers in Plant Science (2024).
2. Effects of green-manure and tillage management on soil microbial community composition, nutrients and tree growth in a walnut orchard. Scientific Reports (2021).
3. Soil bacterial communities in three rice-based cropping systems differing in productivity. Scientific Reports (2020).
4. Chinese Milk Vetch Improves Plant Growth, Development and 15N Recovery in the Rice-Based Rotation System of South China. Scientific Reports (2017).
5. Responses of soil microbial metabolism, function and soil quality to long-term addition of organic materials with different carbon sources. Biochar (2024).